The optical properties of liquid crystals can be modified by an applied voltage. Therefore, liquid crystals are commonly used as dielectrics in display devices. Electro-optical devices based on liquid crystals are well known to one skilled in the art.
The liquid crystal materials must have good chemical and thermal stability and good stability to electric fields and electromagnetic radiation. In addition, the liquid crystal materials should have low viscosity and produce short addressing times, low threshold voltages and high contrast in the cells. They should also have a suitable mesophase at the usual operating temperatures, i.e., in the broadest possible range above and below room temperature. Furthermore, since liquid crystals are generally used as mixtures of a plurality of components, it is important that the components are readily miscible with one another. Other properties, such as the electrical conductivity, the dielectric anisotropy and the optical anisotropy, have to satisfy various requirements depending on the cell type and area of application.
With the development of many different types of liquid crystal display devices and elements, there continues to be a great demand for liquid crystal compositions that have many of the properties discussed above. Accordingly, there is a continuing need for liquid crystal compositions that can achieve or meet various properties and/or requirements.